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ATT U-verse TV system

Jul 22nd 2011, 19:22

KF0IQ

Joined: Apr 4th 1998, 00:00
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Total Posts: 0
ATT recently rolled out their U-verse TV system here in town and it is being heavily promoted. I am considering signing up but am concerned about RFI problems especially since I use an attic antenna (off center fed dipole, 100 watt). I have found some negative RFI articles regarding U-verse but that information was not current. Are there any RFI issues I should know about regarding this system? Thanks.
Jul 23rd 2011, 11:37

w1rfi

Super Moderator

Joined: Apr 4th 1998, 00:00
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The reports on U-Verse are stiill mixed. The ARRL Lab has seen the same posts you have found and received reports of U-Verse systems that appear to not cause any problems at all. In a few cases, the U-Verse systems are reported to be noisy, while others seem very susceptible to interference from Amateur Radio.

First, the good news -- the majority of U-Verse installations appear to be problem-free, although most hams that are reporting the 'no-problem' systems do not have the U-Verse installed in their own homes. Still, we do have reports of successful installations. Steve Ford, WB8IMY, the QST Editor has U-Verse installed in his house. Although there were a few initial problems, AT&T resolved them and so far, so good.

At my QTH, U-Verse is in the neighborhood, but not in my house, and I have seen no increase in noise. My antennas are about 300 feet from the U-Verse distibution hub (those big boxes near the street. I run QRP, so it is not likely I would interere with the U-Verse system.

In those cases where hams are interfering with the U-Verse system, under the FCC rules, it is not the responsibility of the ham to address the interference, although when AT&T does work on the system, the cooperation of the involved ham to put a signal on the air for test purposes is appreciated.

The U-Verse signal itself does not appear to be causing interference to Amateur Radio. We do have reports of interference from U-Verse systems, but it appears to be noise from the switching power supply used in the system.

Not all U-Verse installations have immunity problems or cause interference, so the design itself does not appear to be a disaster for ham radio.

ARRL's EMC Engineer, Mike Gruber, w1mg@arrl.org, has established contact with AT&T staff and found them to be very recepetive to finding the problems, especially since they seem to be random in nature. There does not appear to be a single cause of thie problems, and findings so far have ranged from poor internal grounding and bonding in some of the hubs to noisy (defective?) power supplies to the relatively poor telephone wiring found in some neighborhoods.

The cooperation shown by AT&T is laudable and appreciated. AT&T is investigating individual cases and developing service procedures to address them. One of their engineers, Gordon Beattie, W2TTT, has joined the ARRL EMC Committee, a group of hams that work in various parts of industry, advising ARRL staff and the Board of Directors on EMC matters.

All in all, I am pleased with the progress. The flow of technology is inevitable, and as new technologies come down the pike, it is important that compatibility with Amateur Radio be considered in the design and implementation. It is a combination of cooperation by industry, reports from Amateurs and this kind of work by ARRL that will help make a difference.

I'll spice up my usual signature block to provide some examples of how ARRL is addressing these sorts of problems, not to brag but to help members here understand more about ARRL staff work. Work on these committees saves a seat for Amateur Radio at some important industry tables, often in positions of leadership..

73,
Ed Hare, W1RFI
ARRL Lab Manager
    ARRL EMC Commitee member
    IEEE EMC Society member
    IEEE EMC Society Standards Development Committee - Secretary
    ANSI asc C63 Committee (EMC) - Member, Vice Chair Immunity Subcommittee, Chair of the below 30 MHz measurement task group
    IEEE Connecticut Section Vice Chair
    University of Hartford Industry Advisory Committee - Member
    QRP Amateur Radio Club International - Board of Directors
Apr 22nd, 17:57

K5MP

Joined: Apr 4th 1998, 00:00
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Total Posts: 0
I've had u-Verse in my home for about 10 years. Last year I installed a GAP Titan DX vertical antenna mounted on an aluminum fence about 30 feet from the house. I have 5 TVs in the house and the one which is physically nearest the antenna is the only one affected by RFI when I am on the air. I could use direction to help isolate what is causing the problem.....is it spurious radiation from the coax or the vertical antenna, or might it be the fault of either the TV or the U-Verse set top box. I run 100W SSB and CW, and the XYL informs that the TV picture and audio blanks with my voice or by the CW keying. I learned only this week that the same symptom happened when on my new elecraft KX3, running only 15W CW. I don't own a dummy load but was thinking of obtaining one to isolate the problem as being in the coax or from the antenna. I wonder if a low-pass filter at the transmitter end of the feed line would have any effect with today's solid state technology (in the TV).. I do have a Low Pass filter to try next. Additionally I was thinking of moving one of the other flat screen tvs and associated u-verse controller into the position of the failing TV. While I contemplate those suggested diagnostic moves, can you suggest what I might be overlooking, and would you suspect the U-verse set top box could be the culprit? Thanks. Mike Pilgrim, K5MP, Boca Raton, Fl
Apr 22nd, 19:47

W1MG

Joined: Apr 4th 1998, 00:00
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U-Verse customers probably number in the millions by now. Statistically speaking, we've had a surprisingly small number of complaints given from them. Offhand I don't recall any in the last few months and most of the older complaints were resolved.
Apr 22nd, 20:05

W1VT

Joined: Apr 4th 1998, 00:00
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I'd suggest calling Mike Gruber on Monday--it would help if he knew whether the interference was on all channels or just one, or something else.
Apr 22nd, 20:11

K5MP

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Okay. Thanks for the response. I'll do more testing here before I bother Mike. I need to verify if it is on one or more channels. I just now installed a low pass filter at the radio end of the coax and will run some tests later this evening. Lastly, if still no resolution, I will put a different TV and set top box in that location and see if it acts the same.

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